Aligning the two hot ends

[kerog]

I'm having real difficulty getting the two hot ends to be exactly the same height. I've got it pretty close, but can see that one is just a tiny bit higher than the other. Adjusting the vertical bolts doesn't seem to make much difference; due to the problems with the nut around step 57 I have very little sense for what tightening those bolts does, if anything. I have to loosen the horizontal bolts going through the fan to adjust the hot end height. And any little nudge seems to be too coarse.

Since I'm also having trouble getting filament to grab and extrude at all, I'm wondering if I'm going to have to disassemble and reassemble the extruders. Perhaps I should say I'm dreading it, as I imagine it would require rewiring the whole darn thing.

Anyone have some words of wisdom to help me out here?

[Dreide]

Depending on how big the difference between the extruders is, putting a small piece of paper e.g. between extruder and the bottom of the print head, or at one side in the back, between the print head and the carriage, might help. Regarding the vertical screws in the back, which lock the print head to the carriage,I found it helpful to use thick nuts instead of thin nuts (step #57).
Very small differences can be adjusted by tightening the assembly of one or loosening the assembly of the other extruder a tiny little bit (where the cold end meets the hot end via the PEEK). Be careful though to not overturn the PEEK threads.

[Hugues]

maybe you tried this way already but just in case:
- loosen the 2 screws holding the extruder and fans
- lower the 2 extruders to touch the printing bed, slightly
- tighten the screws

it worked for me, although i don't have a lot of mileage yet of my dual extruder,